On Tue, 17 Feb 2004 00:07:45 +0800, "Erica So" <[EMAIL PROTECTED]> wrote:
> To explain why my data are less than one, let me tell u what I do in my > experiment. My experiment is a kind a ecological survey, which involves > counting the number of different animal species in different algae species. > Since the area of algae species are varied, so I will calculate the density > instead of number of individuals. > > eg 6 animal Y was found in 100cm2 algae Z > So, the data (density) that involves in the Chisq = 6/100 = 0.06, but > not 6 individuals. That's why my data are usually less than 1 due to > dividing the area. I do not know what you have for generating a statistic -- but it is certainly *not* a contingency table. The piece of description (above) does not suggest any test at all. Is there any "expected value" for some unit? It is not the same thing as having a "rate" of something. If you want to say that one species exists in groups with densities higher than other species, then you would need to do something to define "groups" and you would need to have multiple counts for each of several species. So, Type1 has density scores of (0.8, 0.7, 0.8, 0.75); while Type 2 has scores of (0.6, 0.55, 0.65, 0.6); and so on. > > Someone suggest me to use the Jaccard's coefficient, however, it seems that > this coefficient is not that common. Can I use the Jaccard's coefficient for > my case? > - You have confused me, so I do not have much idea of what 'your case' is, unless it is what I tried to describe. -- Rich Ulrich, [EMAIL PROTECTED] http://www.pitt.edu/~wpilib/index.html "Taxes are the price we pay for civilization." . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
